RSA加密与解密

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JEECG低代码 2022-04-14 10:03:27

文章标签 RSA 加密解密 java 数据 文章分类 代码人生

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package utils;

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import java.io.ByteArrayOutputStream;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;
import javax.crypto.Cipher;
/**
*
* RSA公钥/私钥/签名工具包
*
*
* 罗纳德·李维斯特（Ron [R]ivest）、阿迪·萨莫尔（Adi [S]hamir）和伦纳德·阿德曼（Leonard [A]dleman）
*
*
* 字符串格式的密钥在未在特殊说明情况下都为BASE64编码格式
* 由于非对称加密速度极其缓慢，一般文件不使用它来加密而是使用对称加密，
* 非对称加密算法可以用来对对称加密的密钥加密，这样保证密钥的安全也就保证了数据的安全
*
*
* @author IceWee
* @date 2012-4-26
* @version 1.0
*/
public class RSAUtils {
/**
* 加密算法RSA
*/
public static final String KEY_ALGORITHM = "RSA";
/**
* 签名算法
*/
public static final String SIGNATURE_ALGORITHM = "MD5withRSA";
/**
* 获取公钥的key
*/
private static final String PUBLIC_KEY = "RSAPublicKey";
/**
* 获取私钥的key
*/
private static final String PRIVATE_KEY = "RSAPrivateKey";
/**
* RSA最大加密明文大小
*/
private static final int MAX_ENCRYPT_BLOCK = 117;
/**
* RSA最大解密密文大小
*/
private static final int MAX_DECRYPT_BLOCK = 128;
/**
*
* 生成密钥对(公钥和私钥)
*
*
* @return
* @throws Exception
*/
public static Map<String, Object> genKeyPair() throws Exception {
KeyPairGenerator keyPairGen = KeyPairGenerator
.getInstance(KEY_ALGORITHM);
keyPairGen.initialize(1024);
KeyPair keyPair = keyPairGen.generateKeyPair();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
Map<String, Object> keyMap = new HashMap<String, Object>(2);
keyMap.put(PUBLIC_KEY, publicKey);
keyMap.put(PRIVATE_KEY, privateKey);
return keyMap;
}
/**
*
* 用私钥对信息生成数字签名
*
*
* @param data
* 已加密数据
* @param privateKey
* 私钥(BASE64编码)
*
* @return
* @throws Exception
*/
public static String sign(byte[] data, String privateKey) throws Exception {
byte[] keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initSign(privateK);
signature.update(data);
return Base64Utils.encode(signature.sign());
}
/**
*
* 校验数字签名
*
*
* @param data
* 已加密数据
* @param publicKey
* 公钥(BASE64编码)
* @param sign
* 数字签名
*
* @return
* @throws Exception
*
*/
public static boolean verify(byte[] data, String publicKey, String sign)
throws Exception {
byte[] keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
PublicKey publicK = keyFactory.generatePublic(keySpec);
Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
signature.initVerify(publicK);
signature.update(data);
return signature.verify(Base64Utils.decode(sign));
}
/**
*
* 私钥解密
*
*
* @param encryptedData
* 已加密数据
* @param privateKey
* 私钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] decryptByPrivateKey(byte[] encryptedData,
String privateKey) throws Exception {
byte[] keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, privateK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher
.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher
.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
/**
*
* 公钥解密
*
*
* @param encryptedData
* 已加密数据
* @param publicKey
* 公钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] decryptByPublicKey(byte[] encryptedData,
String publicKey) throws Exception {
byte[] keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.DECRYPT_MODE, publicK);
int inputLen = encryptedData.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段解密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
cache = cipher
.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
} else {
cache = cipher
.doFinal(encryptedData, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_DECRYPT_BLOCK;
}
byte[] decryptedData = out.toByteArray();
out.close();
return decryptedData;
}
/**
*
* 公钥加密
*
*
* @param data
* 源数据
* @param publicKey
* 公钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] encryptByPublicKey(byte[] data, String publicKey)
throws Exception {
byte[] keyBytes = Base64Utils.decode(publicKey);
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key publicK = keyFactory.generatePublic(x509KeySpec);
// 对数据加密
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, publicK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/**
*
* 私钥加密
*
*
* @param data
* 源数据
* @param privateKey
* 私钥(BASE64编码)
* @return
* @throws Exception
*/
public static byte[] encryptByPrivateKey(byte[] data, String privateKey)
throws Exception {
byte[] keyBytes = Base64Utils.decode(privateKey);
PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
cipher.init(Cipher.ENCRYPT_MODE, privateK);
int inputLen = data.length;
ByteArrayOutputStream out = new ByteArrayOutputStream();
int offSet = 0;
byte[] cache;
int i = 0;
// 对数据分段加密
while (inputLen - offSet > 0) {
if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
} else {
cache = cipher.doFinal(data, offSet, inputLen - offSet);
}
out.write(cache, 0, cache.length);
i++;
offSet = i * MAX_ENCRYPT_BLOCK;
}
byte[] encryptedData = out.toByteArray();
out.close();
return encryptedData;
}
/**
*
* 获取私钥
*
*
* @param keyMap
* 密钥对
* @return
* @throws Exception
*/
public static String getPrivateKey(Map<String, Object> keyMap)
throws Exception {
Key key = (Key) keyMap.get(PRIVATE_KEY);
return Base64Utils.encode(key.getEncoded());
}
/**
*
* 获取公钥
*
*
* @param keyMap
* 密钥对
* @return
* @throws Exception
*/
public static String getPublicKey(Map<String, Object> keyMap)
throws Exception {
Key key = (Key) keyMap.get(PUBLIC_KEY);
return Base64Utils.encode(key.getEncoded());
}
}

Base64Utils文件

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package utils;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import com.sun.org.apache.xml.internal.security.utils.Base64;
/**
*
* BASE64编码解码工具包
*
*
* 依赖javabase64-1.3.1.jar
*
*
* @author IceWee
* @date 2012-5-19
* @version 1.0
*/
public class Base64Utils {
/**
* 文件读取缓冲区大小
*/
private static final int CACHE_SIZE = 1024;
/**
*
* BASE64字符串解码为二进制数据
*
*
* @param base64
* @return
* @throws Exception
*/
public static byte[] decode(String base64) throws Exception {
return Base64.decode(base64.getBytes());
}
/**
*
* 二进制数据编码为BASE64字符串
*
*
* @param bytes
* @return
* @throws Exception
*/
public static String encode(byte[] bytes) throws Exception {
return new String(Base64.encode(bytes));
}
/**
*
* 将文件编码为BASE64字符串
*
*
* 大文件慎用，可能会导致内存溢出
*
*
* @param filePath 文件绝对路径
* @return
* @throws Exception
*/
public static String encodeFile(String filePath) throws Exception {
byte[] bytes = fileToByte(filePath);
return encode(bytes);
}
/**
*
* BASE64字符串转回文件
*
*
* @param filePath 文件绝对路径
* @param base64 编码字符串
* @throws Exception
*/
public static void decodeToFile(String filePath, String base64) throws Exception {
byte[] bytes = decode(base64);
byteArrayToFile(bytes, filePath);
}
/**
*
* 文件转换为二进制数组
*
*
* @param filePath 文件路径
* @return
* @throws Exception
*/
public static byte[] fileToByte(String filePath) throws Exception {
byte[] data = new byte[0];
File file = new File(filePath);
if (file.exists()) {
FileInputStream in = new FileInputStream(file);
ByteArrayOutputStream out = new ByteArrayOutputStream(2048);
byte[] cache = new byte[CACHE_SIZE];
int nRead = 0;
while ((nRead = in.read(cache)) != -1) {
out.write(cache, 0, nRead);
out.flush();
}
out.close();
in.close();
data = out.toByteArray();
}
return data;
}
/**
*
* 二进制数据写文件
*
*
* @param bytes 二进制数据
* @param filePath 文件生成目录
*/
public static void byteArrayToFile(byte[] bytes, String filePath) throws Exception {
InputStream in = new ByteArrayInputStream(bytes);
File destFile = new File(filePath);
if (!destFile.getParentFile().exists()) {
destFile.getParentFile().mkdirs();
}
destFile.createNewFile();
OutputStream out = new FileOutputStream(destFile);
byte[] cache = new byte[CACHE_SIZE];
int nRead = 0;
while ((nRead = in.read(cache)) != -1) {
out.write(cache, 0, nRead);
out.flush();
}
out.close();
in.close();
}
}

测试用例：

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package util;
import java.util.Map;
import RSAUtils;
public class RSATester {
static String publicKey;
static String privateKey;
static {
try {
Map<String, Object> keyMap = RSAUtils.genKeyPair();
publicKey = RSAUtils.getPublicKey(keyMap);
privateKey = RSAUtils.getPrivateKey(keyMap);
System.err.println("公钥: \n\r" + publicKey);
System.err.println("私钥： \n\r" + privateKey);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws Exception {
test();
testSign();
}
static void test() throws Exception {
System.err.println("公钥加密——私钥解密");
String source = "这是一行没有任何意义的文字，你看完了等于没看，不是吗？";
System.out.println("\r加密前文字：\r\n" + source);
byte[] data = source.getBytes();
byte[] encodedData = RSAUtils.encryptByPublicKey(data, publicKey);
System.out.println("加密后文字：\r\n" + new String(encodedData));
byte[] decodedData = RSAUtils.decryptByPrivateKey(encodedData, privateKey);
String target = new String(decodedData);
System.out.println("解密后文字: \r\n" + target);
}
static void testSign() throws Exception {
System.err.println("私钥加密——公钥解密");
String source = "这是一行测试RSA数字签名的无意义文字";
System.out.println("原文字：\r\n" + source);
byte[] data = source.getBytes();
byte[] encodedData = RSAUtils.encryptByPrivateKey(data, privateKey);
System.out.println("加密后：\r\n" + new String(encodedData));
byte[] decodedData = RSAUtils.decryptByPublicKey(encodedData, publicKey);
String target = new String(decodedData);
System.out.println("解密后: \r\n" + target);
System.err.println("私钥签名——公钥验证签名");
String sign = RSAUtils.sign(encodedData, privateKey);
System.err.println("签名:\r" + sign);
boolean status = RSAUtils.verify(encodedData, publicKey, sign);
System.err.println("验证结果:\r" + status);
}
}

生成RSA密钥、保存到文件、从文件读取、加密、解密等操作

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import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import javax.crypto.Cipher;
import org.apache.commons.configuration.ConfigurationException;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
public class RSATest {
public static void main(String[] args) {
try {
RSATest encrypt = new RSATest();
String encryptText = "encryptText";
// Generate keys
KeyPair keyPair = encrypt.generateKey();
RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
byte[] e = encrypt.encrypt(publicKey, encryptText.getBytes());
byte[] de = encrypt.decrypt(privateKey, e);
System.out.println(toHexString(e));
System.out.println(toHexString(de));
} catch (Exception e) {
e.printStackTrace();
}
}
public KeyPair generateKey() throws NoSuchAlgorithmException {
KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA");
keyPairGen.initialize(1024, new SecureRandom());
KeyPair keyPair = keyPairGen.generateKeyPair();
return keyPair;
}
public void saveKey(KeyPair keyPair, String publicKeyFile,
String privateKeyFile) throws ConfigurationException {
PublicKey pubkey = keyPair.getPublic();
PrivateKey prikey = keyPair.getPrivate();
// save public key
PropertiesConfiguration publicConfig = new PropertiesConfiguration(
publicKeyFile);
publicConfig.setProperty("PULIICKEY", toHexString(pubkey.getEncoded()));
publicConfig.save();
// save private key
PropertiesConfiguration privateConfig = new PropertiesConfiguration(
privateKeyFile);
privateConfig.setProperty("PRIVATEKEY",
toHexString(prikey.getEncoded()));
privateConfig.save();
}
/**
* @param filename
* @param type：
* 1-public 0-private
* @return
* @throws ConfigurationException
* @throws NoSuchAlgorithmException
* @throws InvalidKeySpecException
*/
public Key loadKey(String filename, int type)
throws ConfigurationException, NoSuchAlgorithmException,
InvalidKeySpecException {
PropertiesConfiguration config = new PropertiesConfiguration(filename);
KeyFactory keyFactory = KeyFactory.getInstance("RSA",
new BouncyCastleProvider());
if (type == 0) {
// privateKey
String privateKeyValue = config.getString("PULIICKEY");
PKCS8EncodedKeySpec priPKCS8 = new PKCS8EncodedKeySpec(
toBytes(privateKeyValue));
PrivateKey privateKey = keyFactory.generatePrivate(priPKCS8);
return privateKey;
} else {
// publicKey
String privateKeyValue = config.getString("PRIVATEKEY");
X509EncodedKeySpec bobPubKeySpec = new X509EncodedKeySpec(
toBytes(privateKeyValue));
PublicKey publicKey = keyFactory.generatePublic(bobPubKeySpec);
return publicKey;
}
}
/**
* Encrypt String.
*
* @return byte[]
*/
protected byte[] encrypt(RSAPublicKey publicKey, byte[] data) {
if (publicKey != null) {
try {
Cipher cipher = Cipher.getInstance("RSA",
new BouncyCastleProvider());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
return cipher.doFinal(data);
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
/**
* Basic decrypt method
*
* @return byte[]
*/
protected byte[] decrypt(RSAPrivateKey privateKey, byte[] raw) {
if (privateKey != null) {
try {
Cipher cipher = Cipher.getInstance("RSA",
new BouncyCastleProvider());
cipher.init(Cipher.DECRYPT_MODE, privateKey);
return cipher.doFinal(raw);
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
public static String toHexString(byte[] b) {
StringBuilder sb = new StringBuilder(b.length * 2);
for (int i = 0; i < b.length; i++) {
sb.append(HEXCHAR[(b[i] & 0xf0) >>> 4]);
sb.append(HEXCHAR[b[i] & 0x0f]);
}
return sb.toString();
}
public static final byte[] toBytes(String s) {
byte[] bytes;
bytes = new byte[s.length() / 2];
for (int i = 0; i < bytes.length; i++) {
bytes[i] = (byte) Integer.parseInt(s.substring(2 * i, 2 * i + 2),
16);
}
return bytes;
}
private static char[] HEXCHAR = { '0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
}

Java中RSA非对称密钥加解密使用示例

一、简介：

　　RSA加密算法是最常用的非对称加密算法，CFCA在证书服务中离不了它。RSA是第一个比较完善的公开密钥算法，它既能用于加密，也能用于数字签名。这个算法经受住了多年深入的密码分析，虽然密码分析者既不能证明也不能否定RSA的安全性，但这恰恰说明该算法有一定的可信性，目前它已经成为最流行的公开密钥算法。

　　二、RSA的公钥、私钥的组成，以及加密、解密的公式可见于下表

　　三、使用方式：

　　① 假设A、B机器进行通信，已A机器为主；

　　② A首先需要用自己的私钥为发送请求数据签名，并将公钥一同发送给B；

　　③ B收到数据后，需要用A发送的公钥进行验证，已确保收到的数据是未经篡改的；

　　④ B验签通过后，处理逻辑，并把处理结果返回，返回数据需要用A发送的公钥进行加密（公钥加密后，只能用配对的私钥解密）；

　　⑤ A收到B返回的数据，使用私钥解密，至此，一次数据交互完成。

　　四、代码示例：

　　1、第一步获取私钥，为签名做准备。

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